1. Watch and feel to tell whether they are working to my expectations. Those expectations are based upon how they worked with a fresh coat of abrasive.
2. I clean with minimal alcohol and recoat. I only use the sandpaper when surface irregularities become an issue, or when an alcohol wipe just doesn’t get it. I have had lots of my strops in use for well over two years and lots of knives.. I have lapped them once.
3. If they are solid black… well it probably means a bit of cleaning is in order. Of course, after cleaning you need to recoat them.
That is for leather. I don’t use my balsa strops that much. When they need attention, I will likely follow the same protocol.
I’ve just reloaded my strops, and it does make a huge difference. I wasn’t able to get them completely clean though before reloading them. I just made sure that I put the same paste on each one. 😛
